A boot is a type of footwear that encases both the foot and a portion of the lower leg of a user. Boots are generally manufactured for a particular purpose or activity and therefore are designed to include characteristics consistent with the intended purpose. For example, a hiking boot is designed to support the ankle of a user while minimizing the overall weight. Likewise, a ski boot is designed to maximize a user's performance at a particular skiing activity.
Boots generally include a shell, a compression system, and a sole. The shell and compression system operate to encase and support the foot and lower leg of a user. Various well-known shell and compression systems are utilized to allow users to insert and remove their feet in an open boot configuration and compress the shell around the foot in a closed boot configuration. The sole of a boot is disposed on the bottom surface of the shell and sole is generally composed of a rubber or plastic material. The sole may consist of a single piece or multiple blocks. The stiffness and/or weight characteristics of the sole have an effect on the overall performance of the boot.
The general activity of skiing comprises many subset activities including but not limited to alpine touring, telemark, and downhill. Each subset of skiing generally corresponds to a unique system of specialized equipment. For example, the boot, ski, and binding systems used for telemark skiing are significantly different from those used for alpine touring. A skiing system may include standard types of boots, skis, and bindings. Each type of skiing also corresponds to unique characteristics of a boot to achieve optimal performance. In addition, particular terrain and skier preference may require an even more specific set of performance characteristics. Boots for particular skiing activities must be compatible with the remainder of the system. For example, telemark skiing boots have generally been required to conform to the 75 mm standard to allow for compatibility with telemark type bindings.
Telemark skiing requires that a user be able to pivot or rotate their foot with respect to the corresponding ski in the metatarsal foot bone region. Most conventional telemark boot binding interface systems utilize an extended sole portion called a duckbill to couple the boot to the binding and ski. The proper rotational freedom is then controlled by the flexibility properties of the boot and duckbill. This system requires that the duckbill and toe region of the boot be sufficiently rigid to prevent undesired rotation or torsion about the duckbill. This required rigidity necessitates relatively heavy materials for both the duckbill and toe portion of the boot. In addition, this duckbill boot binding interface creates a toe-biased pivot that is difficult to adjust without also affecting undesired movements such as torsion.
Therefore, there is a need in the industry for a boot binding interface system that enables releasable rotatable coupling while minimizing weight and optimizing telemark performance.